The Router That Ignored the Shorter-Looking Route
A router can match more than one route. The winner is the most specific matching prefix, not simply the first or broadest entry.
Subject: Electrical Computer
The 1500-Byte Packet That Did Not Arrive in 12 Microseconds
A fast bit rate reduces serialization time, but it does not remove the physical travel time across the link.
The /27 Network That Could Not Fit 40 Devices
A /27 contains 32 addresses, but not all 32 can be assigned to ordinary hosts in a conventional IPv4 subnet.
The Four-Channel FDM Link That Needed 95 kHz
FDM channel bandwidths are not the whole spectrum plan. Guard bands between channels also consume frequency space.
The PCM Link That Needed 64 kbps, Not 32
Analog bandwidth is not the same as sampling rate. A 4 kHz voice signal can produce a 64 kbps PCM stream.
The AM Signal Whose Envelope Pinched Shut
A stronger message signal can break conventional AM envelope detection when the modulation index exceeds 1.
The Higher-Gain Loop That Crossed Into Instability
Higher controller gain can reduce error and still destabilize a feedback loop. The characteristic equation sets the allowable range.
The Bode Plot That Lost 20 dB in One Decade
A DC gain of 100 gives 40 dB only in the low-frequency region. A first-order pole changes the slope above its corner.
The Gain-10 Loop That Only Reached 0.909
A forward-path gain of 10 does not mean a closed-loop gain of 10. Reduce the feedback loop before predicting output.
The 8 Ohm Load That Became 128 Ohms
Voltage scales with turns ratio, but impedance does not. An 8 ฮฉ load can appear as 128 ฮฉ through a 4:1 transformer.